Diabetes symptoms

Diabetes is often called the silent killer because of its easy-to-miss symptoms. "Almost every day people come into my office with diabetes who don't know it," says Maria Collazo-Clavell, MD, an endocrinologist at the Mayo Clinic in Rochester, Minn.

The best way to pick up on it is to have a blood sugar test. But if you have these symptoms, see your doctor.

Diabetes symptoms

Diabetes is often called the silent killer because of its easy-to-miss symptoms. "Almost every day people come into my office with diabetes who don't know it," says Maria Collazo-Clavell, MD, an endocrinologist at the Mayo Clinic in Rochester, Minn.

The best way to pick up on it is to have a blood sugar test. But if you have these symptoms, see your doctor.

Weight loss

Overly high blood sugar levels can also cause rapid weight loss, say 10 to 20 pounds over two or three months—but this is not a healthy weight loss.

Because the insulin hormone isn't getting glucose into the cells, where it can be used as energy, the body thinks it's starving and starts breaking down protein from the muscles as an alternate source of fuel.

The kidneys are also working overtime to eliminate the excess sugar, and this leads to a loss of calories (and can harm the kidneys). "These are processes that require a lot of energy," Dr. Collazo-Clavell notes. "You create a calorie deficit."

Skin problems

Itchy skin, perhaps the result of dry skin or poor circulation, can often be a warning sign of diabetes, as are other skin conditions, such as acanthosis nigricans.

"This is a darkening of the skin around the neck or armpit area," Dr. Collazo-Clavell says. "People who have this already have an insulin resistance process occurring even though their blood sugar might not be high. When I see this, I want to check their blood sugar."

Yeast infections

"Diabetes is considered an immunosuppressed state," Dr. Collazo-Clavell explains. That means heightened susceptibility to a variety of infections, although the most common are yeast (candida) and other fungal infections, she says. Fungi and bacteria both thrive in sugar-rich environments.

Women, in particular, need to watch out for vaginal candida infections.

Fatigue and irritability

"When people have high blood sugar levels, depending on how long it's been, they can get used to chronically not feeling well," says Dr. Collazo-Clavell. "Sometimes that's what brings them into the office."

Getting up to go to the bathroom several times during the night will make anyone tired, as will the extra effort your body is expending to compensate for its glucose deficiency.

And being tired will make you irritable. "We see people whose blood sugar has been really high, and when we bring the blood sugar down, it's not uncommon that I hear, ‘I didn't realize how bad I felt,'" she says.

Blurry vision

Having distorted vision and seeing floaters or occasional flashes of light are a direct result of high blood sugar levels.

"Blurry vision is a refraction problem. When the glucose in the blood is high, it changes the shape of the lens and the eye," Dr. Collazo-Clavell explains.

The good news is that this symptom is reversible once blood sugar levels are returned to normal or near normal. But let your blood sugar go unchecked for long periods and the glucose will cause permanent damage, possibly even blindness. And that's not reversible.

Still, as with vision, if blood sugar levels are allowed to run rampant for too long, neuropathy (nerve damage) will be permanent. "That's why we try to control blood sugar as quickly and as well as possible," she says.